BATTERY

ELECTRICAL SYSTEM

TESTING AND ADJUSTING

ELECTRICAL SYSTEM

Most of the testing of the electrical system can be done

seconds. Immediately test the battery voltage. A 6 volt

on the engine. The wiring insulation must be in good

battery in good condition will test 4.5 volts; a 12 volt

condition, the wire and cable connections clean and tight

battery in good condition will test 9 volts.

and the battery fully charged. If on the engine test

shows a defect in a component,

remove

the

The Special Instruction (GEG00058) with the

component for more testing.

9S1990 Charger Tester gives the battery testing

procedure.

BATTERY

CHARGING SYSTEM

Tools Needed: 5P300 Electrical Tester.

9S1990 or 1P7470 Battery Charger

Tester.

NOTE: Make reference to Special Instruction

5P957 or 5P3414 Coolant and Battery

(GEG02276) and to the instructions inside of the cover

Tester.

of the tester, when testing with the 5P300 Electrical

Tester.

NOTE: Make reference to Special Instruction

(GEG02276) and to the instructions inside of the cover

The condition of charge in the battery at each

of the tester, when testing with the 5P300 Electrical

regular inspection will show if the charging system is

Tester.

operating correctly. An adjustment is necessary when

the battery is always in a low condition of charge or a

The battery circuit is an electrical load on the

large amount of water is needed (one ounce per cell per

charging unit. The load is variable because of the

week or every 50 service hours). Test the charging

condition of the charge in the battery. Damage to the

units and voltage regulators on the engine, when

charging unit will result, if the connections, (either

possible, using wiring and components that are a

positive or negative) between the battery and charging

permanent part of the system. Off the engine (bench)

unit are broken while the charging unit is charging. This

testing will give an operational test of the charging unit

is because the battery load is lost and there is an

and voltage regulator.

This testing will give an

increase in charging voltage.

indication of needed repair. Final testing will give proof

that the units are repaired to their original operating

High voltage will damage, not only the charging unit

condition.

but also the regulator and other electrical components.

Before starting on the engine testing, the charging

system and battery must be checked. See the following

Steps.

1. Battery must be at least 75% (1.240 Sp. Gr.) full

charged and held tightly in place. The battery

holder must not put too much stress on the

battery.

2. Cables between the battery, starter and engine

ground must be the correct size. Wires and

cables must be free of corrosion and have cable

support clamps to prevent stress on battery

9S1990 BATTERY CHARGER TESTER

connections (terminals).

CAUTION: Never disconnect any charging unit circuit

3. Leads,

junctions,

switches

and

panel

or battery circuit cable from battery when the charging

instruments that have direct relation to the

unit is charging.

charging circuit must give proper circuit control.

Load test a battery that does not hold a charge when

4. Inspect the drive components for the charging

in use. To do this, put a resistance, across the battery

unit to be sure they are free of grease and oil

main connections (terminals). For a 6 volt battery, put a

and are able to drive the load of the charging

resistance of two times the ampere/hour rating of the

unit.

battery. For a 12 'volt battery, put a resistance of three

times the ampere/hour rating.

Let the resistance

remove the charge (discharge the battery) for 15